It is common for businesses and homeowners to have a security system for detecting alarm conditions at their premises and reporting these to a monitoring station. One of the primary functions of the monitoring station is to notify a human operator when one or more alarm conditions have been sensed by detectors installed at a monitored premise.
Detectors may vary from relatively simple hard-wired detectors, such as door or window contacts to more sophisticated battery operated ones such as motion and glass break detectors. The detectors may all report to an alarm control panel at the premises. The control panel is typically installed in a safe location and is connected to a power supply. The control panel is further in communication with the individual detectors to communicate with or receive signals from individual detectors. The communication between the alarm control panel and the detectors can be one or two way, and may be wired or wireless.
Upon being notified of a detected alarm condition, the control panel typically placed a phone call using the public switched telephone network (the “PSTN”) to a monitoring station whose telephone number has been pre-programmed into the panel. At the monitoring station, the call was received by a complementary interface. Thereafter, the panel notified the interface at the monitoring station using a protocol understood by both the panel and monitoring station.
As a single telephone number was used to service many alarm panels, some mechanism to handle call overflow was required. One way of handling call overflow relied on the use of multiple alarm monitoring servers, having phone numbers configured in PSTN “hunt groups”. As is understood, hunt groups were (and still are) supported by many private branch exchanges (PBX) and centrex services. Hunt groups allowed calls to a single telephone number to be transferred to other lines associated with other numbers in a group, in the event the line of the single number is busy or unavailable. In this way, multiple alarm monitoring servers, each with their own phone lines, configured in a hunt group, could be used to service calls from many panels. At the same time, the load placed on the collection of servers could be balanced.
Modern alarm system designs are moving away from use of the PSTN and are instead relying on packet switched data networks, like the Internet. In such systems, load sharing may be accomplished by fairly assigning different alarm panels to different servers. This may be done manually by installers so that different panels contact different servers. Such manual intervention, however, is cumbersome and may be error prone.
Accordingly, there remains a need for a methods and devices that allow effective load sharing for alarm systems using such data networks.